1. Field of Invention
The present disclosure relates in general to a redundantly sealing a line blind valve. More specifically, the present disclosure relates to a line blind valve with a redundant seal ring formed by injection of a sealant.
2. Description of Related Art
Fluids handling circuits in use in industrial facilities for transmitting fluids typically include lengths of piping and various pieces of fluids handling equipment, where the piping interconnects between the various pieces of the fluids handling equipment. The fluids handling equipment can range from multistory fractionation towers, storage tanks, pumps, compressors, and drums to much smaller items, such as specialty piping equipment, e.g. steam traps, strainers, and filters. What hardware is taken out of service depends on the specific situation, but the particularly hardware actually taken out of service can include a single component within a piping circuit, two or more components in the piping circuit, a section of the length of piping, or an entire circuit. The out of service time period can be as short as a few hours, can be months, or can be permanent. While out of service, the specific portion of a piping circuit is generally isolated from the rest of the piping circuit. Fluid within the out of service piping circuit is typically drained or vented from within the equipment. If required, personnel can safely perform maintenance on, or repair of, the hardware after the fluid has been removed.
Usually included within most piping circuits are valves that can block or isolate portions of the piping circuit being isolated. These valves are sometimes also utilized to isolate the portion of the piping circuit being taken out of service. However, out of service isolation using valves is typically only done when the out of service time period is relatively short, i.e. less than a day. More typically, blinds, such as line blind valves, are used for isolating all or portions of a piping circuit. Blinds, which are usually planar members, have a solid portion that are transversely installed in a pipe and that block fluid communication through the pipe. Blind valve assemblies typically include a blind that can be swung between open and closed positions through different mechanisms that basically force the joint to relax and hence, allow blind to be swung. An O-ring seal is usually provided on the mating surfaces of the blind within the line blind valves and the flanges for preventing fluid from escaping across the blind to ambient. The O-ring seals though can become damaged, either over time or mechanically while being installed, thereby forming a leak path for fluid within a live portion of the piping circuit.